numere pare 2a
consecutive , pare , din 2 in 2
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2a 2·24 cm= 48 cm
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2a +2 2· 24 cm + 2cm =50 cm
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2a + 2 +2 2·24 cm +2cm+2cm = 52 cm
perimetrul = 2a + 2a+2 + 2a+ 2+2 =150 ; 6a + 6 =150 ; 6a =150 -6
6a =144 ; a =144:6 = 24